Immunological mapping in hereditary epidermolysis bullosa

Hereditary epidermolysis bullosa: clinical-epidemiological profile of 278 patients at a tertiary hospital in São Paulo, Brazil

BACKGROUND

Epidermolysis bullosa (EB) is a group of rare hereditary diseases, characterized by fragility of the skin and mucous membranes. Epidemiological data on EB in Brazil are scarce.

OBJECTIVES

To describe epidemiological aspects of patients with EB diagnosed in the Dermatology Department of a tertiary hospital, from 2000 to 2022.

METHODS

An observational and retrospective study was conducted through the analysis of medical records. The evaluated data included clinical form, sex, family history, consanguinity, age at diagnosis, current age, time of follow-up, comorbidities, histopathology and immunomapping, presence of EB nevi and squamous cell carcinomas (SCC), cause of and age at death.

RESULTS

Of 309 patients with hereditary EB, 278 were included. The most common type was dystrophic EB (DEB), with 73% (28.4% dominant DEB, 31.7% recessive DEB and 12.9% pruriginous DEB). Other types were junctional EB with 9.4%, EB simplex with 16.5% and Kindler EB with 1.1%. Women accounted for 53% and men for 47% of cases. Family history was found in 35% and consanguinity in 11%. The mean age at diagnosis was 10.8 years and the current age was 26 years. The mean time of follow-up was nine years. Esophageal stenosis affected 14%, dental alterations affected 36%, malnutrition 13% and anemia 29%. During diagnostic investigation, 72.6% underwent histopathological examination and 92% underwent immunomapping. EB nevi were identified in 17%. Nine patients had SCC. Eleven patients died.

STUDY LIMITATIONS

Insufficient data included to medical records, loss to follow-up, and unavailability of genetic testing.

CONCLUSIONS

In this study, dystrophic EB predominated and the need for multidisciplinary care for comorbidities and complications was highlighted.

Assessing the quality of life in the families of patients with epidermolysis bullosa: The mothers as main caregivers

Background

Epidermolysis bullosa (EB) is an uncommon group of inherited disorders characterized by skin blistering after friction or mechanical trauma. EB affects patients and their families physically, socially, and emotionally.

Objective

This study aimed to assess the family quality of life of these patients using the Family Dermatology Life Quality Index (FDLQI) questionnaire.

Methods

In this cross-sectional study, we enrolled caregivers of patients with EB registered at the Molecular Dermatology Research Center, affiliated with Shiraz University of Medical Sciences, up to 2020. Participants filled out a demographic data collection form and the FDLQI questionnaire. The data were analyzed using SPSS software, version 22.

Results

Overall, 80 participants, consisting of 65 mothers (81.2%) and 15 fathers (18.7%) as primary caregivers, were enrolled in this study. The average FDLQI score was 19.88 ± 4.71. The FDLQI scores of caregivers of patients with EB simplex was significantly lower than scores observed in those with other types of EB (p < .001). There was a significant positive association between the number of patients with EB in the family and FDLQI score (p = .049). FDLQI scores were lower in caregiving mothers who had a higher education (p < .001) and those who were employed (p < .001).

Conclusion

Family quality of life is affected in patients with EB. Families with lower socioeconomic status and unemployed caregivers require special attention. More studies are needed to determine the parameters involved in the quality of life of patients with EB and their families.

Utility of Immunofluorescence Antigen Mapping in Hereditary Epidermolysis Bullosa

Background

Epidermolysis bullosa (EB) is characterized by blisters and erosions on the trauma-prone areas of the body. It occurs as a result of mutation in the genes encoding structural proteins. Transmission electron microscopy (TEM) is considered the gold standard test in the laboratory diagnosis of EB. However, this test requires a lot of expertise and is not widely available. Immunofluorescence antigen mapping (IFM) is considered a suitable alternative with comparable sensitivity and specificity. However, there is paucity of studies analyzing the utility of IFM in the diagnosis of EB.

Aims and Objectives

To study the utility of IFM in the laboratory diagnosis of EB.

Materials and Methods

A cross-sectional study was conducted involving 179 biopsy specimens of patients with EB. IFM was carried out using a panel of monoclonal antibodies against K14, laminin 332, type IV collagen, and type VII collagen.

Results

Diagnosis of EB simplex (EBS), junctional EB (JEB), and dystrophic EB (DEB) was made in 104, 28, and 26 biopsy specimens, respectively. The overall concordance rate was 41.3% with higher concordance rates in EBS.

Conclusion

The present study is conducted to assess the efficacy of IFM in the diagnosis of EB with large sample size. Our study serves to establish IFM as an important tool in the diagnostic armamentarium of EB as the prognosis mainly rests on diagnosing the type of EB.

Gene panel for the diagnosis of epidermolysis bullosa: proposal for a viable and efficient approach

Background

Epidermolysis bullosa is characterized by cutaneous fragility and blistering. Historically, diagnosis is achieved by immunofluorescence mapping or transmission electron microscopy, both involving biopsy procedures. Genetic analysis, especially through next-generation sequencing, is an important tool for the diagnosis of this disease. In Brazil, access to diagnostic methods is limited, and consequently, most patients do not have an accurate diagnosis. Diagnosis allows the indication of prognosis and genetic counselling of the patient.

Objectives

To evaluate the cost-effectiveness of a gene panel compared to immunofluorescence mapping and transmission electron microscopy by analyzing its benefits, limitations, and economic aspects.

Methods

The gene panel included the 11 main genes associated with epidermolysis bullosa. The techniques were compared, assessing the average cost, advantages, and limitations, through a price survey and literature review.

Results

Both immunofluorescence mapping and transmission electron microscopy require skin biopsy, are dependent on the investigator’s expertise, and are subject to frequent inconclusive results. The gene panel is effective for the conclusive diagnosis of epidermolysis bullosa, presents high efficiency and accuracy, is economically feasible, and excludes the need for biopsy. The gene panel allows for prognosis, prenatal genetic diagnosis, and genetic counseling.

Study limitations

It was not possible to find laboratories that perform transmission electron microscopy for epidermolysis bullosa diagnosis in Brazil.

Conclusion

This study supports the gene panel as the first-choice method for epidermolysis bullosa diagnosis.

Reproductive alternatives for patients with dystrophic epidermolysis bullosa

Epidermolysis bullosa describes a group of skin conditions caused by mutations in genes encoding proteins related to dermal-epidermal adhesion. In the United States, 50 cases of epidermolysis bullosa per 1 million live births are estimated, 92% of which classified as simplex, 5% dystrophic, 1% junctional and 2% non-classified. Dystrophic epidermolysis bullosa is associated with autosomal, dominant and recessive inheritance. Epidermolysis bullosa causes severe psychological, economic and social impacts, and there is currently no curative therapy, only symptom control. Embryonic selection is available for epidermolysis bullosa patients in order to prevent perpetuation of the condition in their offspring.

Pretibial dystrophic epidermolysis bullosa

Epidermolysis bullosa is a group of mechano-bullous genetic disorders caused by mutations in the genes encoding structural proteins of the skin. Dystrophic epidermolysis bullosa is caused by mutations in the COL7A1 gene encoding collagen VII, the main constituent of anchoring fibrils. In this group, there are autosomal dominant and recessive inheritances. The pre-tibial form is characterized by the presence of blisters, milia, atrophic scars and lesions similar to lichen planus. The diagnosis is clinical and laboratory and subtypes are distinguished by means of immunohistochemical and ultrastructural studies, in addition to genetic differentiation. Electron microscopy and immunomapping are used in the diagnosis.

Nutritional aspects of children and adolescents with epidermolysis bullosa: literature review

Epidermolysis Bullosa is a genetic disorder that affects mainly the skin, however, all others systems are influenced. The nutritional care of children and adolescents with Epidermolysis Bullosa is a key treatment strategy, since the energy needs are increased due to the disease's metabolism, burdening the immune system and cicatrization process, symptoms caused by the disease hinder the intake and adequate absorption of nutrients, which may result in inadequate growth and development. Because this is a rare disease, there are few professionals who know the characteristics of both the clinical evolution and nutritional and dietary treatments. This literature review discusses the latest knowledge on energy and specific nutrient requirements to the dietary treatment and monitoring of children and adolescents with Epidermolysis Bullosa.

Scanning electron microscopy of a blister roof in dystrophic epidermolysis bullosa

In dystrophic epidermolysis bullosa the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane, with its consequent loss. We performed scanning electron microscopy of an inverted blister roof of a case of dystrophic epidermolysis bullosa, confirmed by immunomapping and gene sequencing. With a magnification of 2000 times a net attached to the blister roof could be easily identified. This net was composed of intertwined flat fibers. With higher magnifications, different fiber sizes could be observed, some thin fibers measuring around 80 nm and thicker ones measuring between 200 and 300 nm.

Comparative scanning electron microscopy of bullous diseases

The purpose of this study is to compare scanning electron microscopy findings of the blister roof in three distinct bullous diseases: one intraepidermal acantholytic (pemphigus foliaceus); one due to hemidesmosomal dysfunction (bullous pemphigoid); and one secondary to anchoring fibril dysfunction - type VII collagen (dystrophic epidermolysis bullosa). In pemphigus foliaceus, acantholytic phenomena were readily demonstrated. In bullous pemphigoid, the epidermis had a solid aspect. In dystrophic epidermolysis bullosa a net was seen in the blister roof.

Inherited epidermolysis bullosa: clinical and therapeutic aspects

Inherited epidermolysis bullosa (EB) is a heterogeneous group of genetic disorders that present with skin and, in some cases, mucosal fragility, predisposing patients to the development of blisters and/or erosions after minimal trauma or friction. Children with a recurrent history of these kinds of lesions or neonates that present them in the absence of another reasonable explanation should be investigated. Diagnosis must be based on clinical and histopathological findings. To date, management of inherited EB basically consists in avoiding traumas that trigger lesions, as well as preventing infection and facilitating healing of the wounds with the systematic use of bandages.

Sporadic Kindler syndrome with a novel mutation

We report the case of a 28-year-old woman with Kindler syndrome, a rare form of epidermolysis bullosa. Clinically, since childhood, she had widespread pigmentary changes in her skin as well as photosensitivity and fragility of the skin and mucous membranes. The mucosal involvement led to an erosive stomatitis as well as esophageal, anal and vaginal stenoses, requiring surgical intervention. The diagnosis of Kindler syndrome was confirmed by DNA sequencing with compound heterozygosity for a nonsense/frameshift combination of mutations (p.Arg110X; p.Ala289GlyfsX7) in the FERMT1 gene.

Clinical variability in dystrophic epidermolysis bullosa and findings with scanning electron microscopy

In dystrophic epidermolysis bullosa, the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane and its consequent loss. A 46 year-old female patient presented blisters with a pretibial distribution associated with nail dystrophy. Her two children had hyponychia and anonychia, which affected all toe nails and the thumb, forefinger and middle finger. DNA sequencing identified in exon 75 of COL7A1 gene a pathologic mutation: c.6235G>A (p.Gly2079Arg). Immunomapping of a blister demonstrated collagen IV (basal membrane) in the blister roof and collagen VII in its floor, confirming dystrophic epidermolysis bullosa. Scanning electron microscopy of an inverted blister showed net-forming collagen attached to the blister roof . The variability found in this family has already been reported and confirms, on a clinical basis, the nail subtype as a dystrophic variant.